1. Field of The Invention
The invention relates to a novel umbrella structure, and in particular, to a novel umbrella structure in which the symmetrical sides with respect to the shaft of the umbrella are connected with surface frames by means of connecting parts so as to increase the opening area of the surface fabric.
2. Description of the Prior Art
Conventional multiple-folding umbrella normally aim at an end of lightweight, thinness and miniature for the convenient carrying by the users. However, those conventional types of multiple-folding umbrella have a relatively limited surface area when they are opened. Consequently, use of multiple-folding umbrella in the rainy day often causes wetting of the user by the rain.
Accordingly, in order to solve the drawback of the limited surface area of the above-mentioned multiple-folding umbrella, folding umbrella with increased overall surface area has been developed, as shown in FIGS. 1 and 2. The umbrella 10 comprises mainly fixing two cross-connecting stretchers 15 and 16 on the shaft 13 by using the shaft 13 as the cross point 14; attaching notches 11a, 11b and runners 12a, 12b on both ends of stretchers 15 and 16, respectively, in a manner that said notches 11a, 11b and runner 12a, 12b are positioned symmetrically on both sides of the shaft 13; connecting inner main ribs 18a, 18b and inner branched rib 17a, 17b of the two-folding rib at a position between said notches 11a, 11b and said runners 12a, 12b such that the object of increasing surface area can be achieved. However, since the lengths of said inner main ribs 18a, 18b and said inner branched ribs 17a, 17b must be equal to the distance from runners 12a, 12b or notches 11a, 11b to the cross point 14 of the two stretchers 15, 16 such that the umbrella 10 can be opened or closed, when it applies to the two-folding type of ribs, a maximum surface area can be obtained, but in case of umbrella with three- or more folding type of ribs, lengths of main ribs 18a, 18b and branched ribs 17a, 17b are invariably less than those in case of two-folding type, leading to the correspondingly shortening of lengths of stretchers 15, 16 and hence the dramatically decreasing of surface area. Thus, though that structure of umbrella 10 can increase the surface area, it cannot apply to other multiple folding types of ribs. Furthermore, during opening or closing of said umbrella 10, moving of stretchers 15, 16 can be done only through driving by assisting stretchers 19a, 19b, 19c, and 19d, resulting in not only a complicated structure but also time-consuming and cost increasing that can not meet the economical efficacy.
Therefore, the above-mentioned conventional umbrella has still many drawbacks and is not a well designed one that further improvement is needed.
In view of the various disadvantages associated with the conventional multiple folding type of umbrella, the inventor has aimed at improving and creating, and, after extensive and comprehensive studies, developed successfully an umbrella with novel structure and thus accomplished the invention.
One object of the invention is to provide a novel umbrella structure in which upper and sub-runners are provided on symmetrical sides with respect to the shaft of the umbrella, and surface frames are connected on both symmetrical sides of the shaft by means of connecting parts formed by cross-engaging two ribs so as to increase the opening area of the surface fabric.
Another object of the invention is to provide a novel umbrella structure wherein connecting parts are provided and connected on both sides symmetrical with respect to the shaft such that it can retain a larger surface area as it applies to two-, three- or four-folding type of the shaft.
Still another object of the invention is to provide a novel umbrella structure wherein, unlike conventional umbrella that stretchers can only be driven by means of assisting stretchers, connecting parts formed by cross-engaging two ribs are linked directly to upper and main runners such that said connecting parts can move as the main runners runs up and down, and functions of a simple structure, easy fabricating and cost lowering can be achieved.
With advantages described above, the novel umbrella structure according to the invention comprises a shaft, two surface frames, upper and main runners, and two connecting parts; wherein said main notch is fixed at the top of said shaft while said main runner is provided as a sleeve around said shaft and can slide up and down along said shaft; wherein said surface frames are consisting of upper and sub-runners linked by main ribs and branched ribs; wherein an umbrella surface is provided covering said main ribs such that it can be opened and closed by virtue of the relative moving of said upper and sub-runners; wherein said connecting parts is formed mainly by cross-engaging of two ribs in a manner that both ends of the first rib are connected to a main notch and a sub-runner, while both ends of the second rib are connected to a main runner and a sub-notch such that the two surface frames can be linked symmetrically at both sides by means of said two connecting parts, and as said main runner slides up and down over said shaft, the distance it slide over can be transferred via said connecting parts, resulting change of positions of said two sub-runners, so as to achieve the function of increasing surface area of the umbrella.